1. Field of the Invention
The present invention relates to online advertising, and in particular, to search retargeting.
2. Background Art
A search engine is an information retrieval system used to locate documents and other information stored on a computer system. Search engines are useful at reducing an amount of time required to find information. One well known type of search engine is a Web search engine which searches for documents, such as web pages, on the “World Wide Web.” Examples of such search engines include Yahoo! Search™ (at http://www.yahoo.com), Bing™ (at http://www.bing.com), and Google™ (at http://www.google.com). Online services such as LexisNexis™ and Westlaw™ also enable users to search for documents provided by their respective services, including articles and court opinions. Further types of search engines include personal search engines, mobile search engines, and enterprise search engines that search on intranets, among others.
To perform a search, a user of a search engine supplies a query to the search engine. The query contains one or more words/terms, such as “hazardous waste” or “country music.” The terms of the query are typically selected by the user to as an attempt find particular information of interest to the user. The search engine returns a list of documents relevant to the query. In a Web-based search, the search engine typically returns a list of uniform resource locator (URL) addresses for the relevant documents, which is displayed to the user in a search results page. If the scope of the search resulting from a query is large, the returned list of documents may include thousands or even millions of documents.
“Sponsored search” refers to a form of Internet advertising/marketing that enables advertisers to increase their visibility in the results page of a search engine query. According to sponsored search, an advertiser may pay or provide other compensation for having an advertisement (or “ad”) appear in a sponsored section of the results page for one or more particular queries. A user who enters one of the queries into the search engine is provided with a results page that includes the advertisement in the sponsored search section. The sponsored search section is prominently displayed in the results page, to enable the user to easily see and interact with the advertisement.
Display advertising is a form of online advertising where advertisements are displayed alongside online content on web pages. Display advertisements may be displayed in various forms, including in the form of banner ads, pop-up ads, etc. A particular display advertisement may be selected for display based on attributes of the user viewing a web page on which the display advertisement is to be displayed, such as the viewer's age, etc.
Advertisers frequently advertise products and/or services online in the form of an “advertising campaign.” An advertising campaign typically includes a set of advertisements provided by an advertiser that share a theme to make up an integrated marketing communication. Advertisement serving systems enable advertisers to set up advertising campaigns to target particular advertisement impressions. Advertising campaigns are frequently configured to include advertisements to be displayed in the form of display advertising.
Search retargeting (SRT) is a form of online advertising where advertisements of advertising campaigns are displayed against user search histories in the form of display advertising. The purpose of SRT is to continue targeting users after they have performed searches and have viewed the resulting search results pages. After a user performs a search and views the search results, the user may browse additional web pages where display advertisements may be displayed. According to SRT, display advertisements may be selected for display to the user based on the search keywords entered by the user when the user was previously searching. If the search keywords used during the searching by the user match keywords provided by an advertiser, an advertisement of the advertiser may be selected for display to the user as a display ad.
An advertiser may submit a SRT segment that includes a set of keywords that may be used to match search keywords entered by users to cause an advertisement of the advertiser to be selected for display. The advertiser may desire to receive an estimate of advertisement inventory for their submitted SRT segment, which is an estimation of how many deliverable advertisements impressions are available for the set of keywords over some time period (e.g., daily, weekly, monthly, etc.). Based on the inventory estimation, the advertiser may modify the set of keywords of the SRT segment to better meet their campaign goals. However, inventory estimation for SRT is difficult because of its relationship to both sponsored search and display advertising.